Comparison of Two Protocols of Agar Gel Immunodiffusion (AGID) Used to Diagnose of Equine Infectious Anemia (EIA)

Abstract

The aim of the present study was to compare two protocols of Agar Gel Immunodiffusion (AGID) that can be used to diagnose Equine Infectious Anemia (EIA). Different volumes of reagents and support for agar gel were used, as recommended by the Ministry of Agriculture, Livestock and Food Supply (MAPA) and the World Organization for Animal Health (OIE). Equidae sera samples (n = 1000) were tested using a national commercial kit and different volumes (i.e. 25 µL—MAPA and 50 µL—OIE) of reagents and standard sera. Antigen was used as recommended by MAPA. The re-sults were assessed by two operators, 48 hours after beginning the test. At the end of the ex-periment, a Kappa index of 1 was obtained by the operators, for the interpretation of the results and for the different volumes of reagents used. Similar results of agreement (Kappa index = 1) were obtained when using slides or Petri dishes as support for the agar gel. In both cases, an al-most perfect agreement was achieved, suggesting that the use of different supports does not affect the results. These findings indicate that both protocols (MAPA and OIE) can be used to diagnose EIA.